Micron control for air separators



July 20, 1937. c. E. HERMANN 2,087,645

MICRON CONTROL FOR AIR SEPARATORS Filed July 22, 19:53 a Sheets-Sheet 1 By #MM.

' Filed July 22, 1935 s Sheets-Sheet 2 Y Z I 0 My 0, v aw W g a W M 0 d 6 WM J J a. m M 6- 7 u ll M i I fi 4. a "m I .5 J J J 6 a v I 4 6 F a J a 2 J July 20, 1937. c. E. HERMANN 2,087,645

IICRON CONTROL FOR AIR SEPARATORS Filed July 22, 1933 5 Sheets-Sheet 5 Rye/afar dizqrlga 15 0mm Wm 174'.

Patented July 20, 1937 UNITED srAT s PATENT OFFICE 2,087,645 IVIICRON CONTRQL FOR AIR SEPARATOR S Giggles Edward Hermann, St. Louis, Mo. Application July 2Z 1933, Serial No. 681,682

4 Claims. I (Cl. 209-144) This invention relates to new and useful improvements in air separators of the type disclosed in my copending application filed August 13, 1931, serial No. 556,477.

In this type of separator the pulverized material is conveyed by currents of air from the grinder into the separator through a plurality of inlets formed in the circumferential wall of the separator near the top thereof. The separator is connected by a suitable pipe to an exhaust fan and the air currents utilized to convey the material to the separator are produced by suction created by said fan. The material upon entering the separator receives circular centrifugal motion which causes the coarse material to drop to the bottom of the separator while the fine material is conveyed out of the separator through the discharge pipe. This swirlingmotion is imparted to the air and to the material through the medium of vanes or deflector plates which are arranged adjacent to the inlets and extend inwardly therefrom into the separator and control the direction of flow of the air.

As is well known in the art, the finest screen i that can be made is 400 mesh so that particles of material of 1/400 of an inch can be measured or passed by said screen. Particles smaller than this size are commonly measured by microns. A micron is 1/10000 of a centimeter or approximately 1/25400 of an inch. In order to obtain a knowledge of the average particle size of a pigment or similar material, it is customary to count the number of particles of different micron sizes when observed through a very powerful microscope and to obtain from them an average particle size.

In most cases the finer the average particle the more desirable it is for use as paint pigment because it will stay in suspension better and absorb more oil due to the increased total surface.

With an ordinary air separator a product may be ninety-nine percent (99%) through 300 mesh and yet have a comparatively coarse average particle size.

One object of the present invention is to provide a device of the class described whereby the average particle size of the ground product can be varied or controlled at a given vane setting.

Other objects of the invention are to provide a ring which is movably mounted so as to adjust the area of the opening between the outer and the inner cone members, thereby regulating the flow of air therebetween.

Further objects of the invention are to provide simple means for actuating such ring and holding it in adjusted position.

Additional objects of the invention are to provide a simple micron control for air separators and classifying equipment which is of simple con- 5 struction, can be easily operated and adjusted, and which insures the production of more finely ground material then produced heretofore.

With these and other objects in view, my invention consists incertain novel features of construction and arrangement of parts, hereinafter arrangement of the separator and the parts associated therewith.

Figure 2 is an enlarged vertical cross section, partly broken away of the separator.

Figure 3 is a horizontal cross section taken on line 3-3 Of Figure 2.

Figure 4 is an enlarged fragmental horizontal cross section.

Figure 5 is an enlarged vertical cross section taken on line 55 of Figure 3. I

Figure 6 is a fragmental detail cross section of a modified form of my invention.

Figure 7 is a fragmental detail cross section showing the adjustable member movable downwardly.

Referring by numerals to the accompanying drawings, l0 indicates a separator, the lower end i I of which is connected by a conduit l2-to a feeder M. This feeder or source of supply of material may be of any desired construction. It may be,

' for instance, in the form of a mill wherein the material is reduced to suitable degrees of fineness before being admitted into the separator. Leading from the upper end of the separator is a conduit [5 which connects to the inlet of a suitable exhaust fan Hi. This fan produces suction in the separator, thereby causing air to flow from the feeder through conduit l2 into said separator. In doing so, the air carries the pulverized material from the feeder to the separator and delivers it therein in a manner hereinafter more fully described, whereby the coarse particles are separated from the fine material. The :oarse material is collected in the separator and the fine material passes through conduit l5 to the exhaust fan It, thence through a conduit H to a cyclone collector l8. The material which is of suitable fineness is collected in this cyclone colleetor and can be discharged through the lower end l9 by opening a suitable gate 20. Preferably the air is returned from the cyclone collector to the feeder through a conduit 2|, thereby permitting recirculation of the air through the systo the return conduit 2|, as indicated at 25. This dust collector may be of any well known construction, the type shown being of the tubular kind.

The object of this dust collector is to dispose of any-excess air that may come into the system through the feeder or otherwise. The dust collects in the lower end of the dust collector and arranged therein. i

The separator I0 is in the form of an inverted cone and consists of an outer shell'26 and an chamber 28 to the lower end of which is connected the discharge end of conduit l2 so that the I pulverized material is discharged into this chamber 29. The inner shell 21 forms a separating chamber 29, the lower end of which terminates in a spout 30 which extends outwardly through shell 26 and is closed by a gate 31. Thus by opening said gate the material collected in chamber 29 can be discharged through said spout.

The upper portion' of outer shell 26 is formed cylindrical as indicated at 32 and the upper portionof the inner shell '21 is similarly shaped as indicated'at 34. These cylindrical portions are concentrically arranged to provide an annular chamber 35 which forms the upper end of the chamber 28..

The upper end of outer shell 26 is closed by a plate 36 which forms the top of the separator and is secured to the end of cylindrical portion 32 in any suitable manner, such as anangle iron ring 31. This top plate is formed with a central opening'in which is received the inlet end of the pipe connection I5.

The upper end of portion 34 of inner shell member 21 terminates a suitable distance below plate 36 to provide a communicating opening between chambers 29 and 35. This circumferential opening is provided with a plurality of spacedapart vertically disposed vanes 38.which divide said opening into a plurality of inlets 39 through which the air carrying the pulverized material enters chamber 29 from chamber 35.

3 These vanes extend between the upper edge of cylindrical portion 34 and plate 36 and their outer edges are disposed within the vertical plane of said cylindrical portion. The upper end of each vane is provided with an upwardly projecting trunnion 40 which is journaled in-top plate 36 and extends thereabove. The lower end of each vane is provided with a downwardly projecting trunnion 4| which is journaled in the horizontally disposed flange of an angle iron ring 42. This ring is secured to the inner side of a collar 44 which latter is secured to the inside of the upper edge of cylindrical portion 34. As shown, the upper edge of collar 44 projects a suitable distance above the lower ends of said vanes. Thus collar 44 not only forms reinforcement'for the upper edge of inner shell 21 but also prevents leakage Of a r P t the lower ends of said vanes.

A ring 45 of angle. iron is secured to the top plate 36 adJacent to and outwardly of the upper ends of'vanes 38. The vertical flange of ring 45 extends downwardly and encircles said vanes and forms a seal toprevent leakage of air past the upper ends of said vanes. 3

The vanes are settangentially to the axis of chamber 29 so that the air and the ground material carried thereby, .upon entering said chamber, receive whirling motion. The centrifugal force causes the coarse particles of material to be separated from the air and from the finer particles and to be collected in the lower end of the separating chamber 29 while the air and fine material is discharged from the chamber through pipe connection l 5.

vanes 38 are arranged comparatively close I together and they are. comparatively deep or of can be discharged therefrom by a suitable valve substantial widths so that each inlet 39 formed by the vanes is narrow and deep. This serves to direct the currents of air in proper direction and impart thereto the desired whirling motion and prevents the formation of stray currents which would impair the efficiency of the separator.

The cylindrical portions 32 and 34 of shells 26 and 21-, respectively, are secured together in spaced-apart relationship by means of a plurality of spacers 46 arranged equidistant about the axis of the separator. Each spacer is substantially of U-shape and the shorter or inner arm'46a. is

tion 34 and to collar 44. The longer or outer arm 46b is secured to the inner face of cylindrical portion 32 and to ring 31. The end 460 of each arm 46!) is preferably bent inwardly in a horizontal plane and extends under and is secured to the underside of plate 36.

Preferably the vanes 38 are mounted so that the tangential angle thereof can be varied as desired. The upper trunnions 40 which project outwardly about plate 36 have each secured thereto an arm 41. Each arm is slotted in its end and engaging said slot is a vertically disposed pin 43 fixed to and depending from a horizontally disposed ring 49. The latter is movably mounted on plate 36-by means of rollers 50. This ring is movable concentrically of the axis of the separator in either-direction for simultaneously cper- In order to insure production of pulverized ma- I terial which can be measured in microns, I provide a movable means or collar 52 which can be raised or adjusted so as to reduce the opening between chambers 26 and 29. This results in greater velocity of the flow of air and pulverized material carried thereby into separating cham-.

ber 29, thereby increasing the centrifugal action so that a larger amount of comparatively coarse material is deflected downwardly in said chamber and only very fine material is discharged through the pipe l5.

' This collar 52 is arranged externally of the cylindrical portion and is of substantially the same height so that when said collar occupies lowered position (see Fig. 2) its upper end is substantially flush with the upper end of said cylindrical portion.

As the arms 46a of spacers 46 are secured to the outer face of the cylindrical portion 34 and The collar is supported in position by a plurality of rods 55 which extend downwardly through apertures formed in topplate 36 and have their lower ends secured to said collar, as indicated at 56. These rods are spaced equidistant about the axis of the'separator. Each rod occupying position above inlets 6B and movable downwardly to reduce the vertical dimension thereof. This band is operable by means of rods 61 which aresimilar to rods 55 of the preferred form. The inlets 56 are formed in the cylindrical portion 34a of inner cone 21a and the upper end of said portion 34a extends to top wall 36a, while the vanes 38a are spaced therefrom. The upper trunnion 40a of the vanes are lengthened and project upwardly through top 36a.

The provision of a ring or collar between the separating chamber or inner cone member and the annular chamber or the outer cone member, restricting the inlet connections between sa d chambers, insures a finer separation of the pulverized material. By making the ring adjustis p o d With a plurality of Spaced-apart able the areas of said inlets can be regulated to zontally disposed apertures 51. A pin 58 is adapted to be inserted in any one of the aper tures of each rod and is adapted to bear against the upper faceof plate 36, thereby limiting the downward movement of said rod and supporting collar 52 in position within the separator.

the aperture nearest plate 36. To lower the collar, pin 58 is withdrawn from the particular aperture of each rod and is inserted in the next higher aperture, thereby permitting said collar to drop the required distance. The collar 52 can be supported in its lowered position by the horizontal portions 46d of spacers 45. The collar 52 canbe easily operated, increases the efficiency of the separator, and enables the production of finer average particle size pulversized material.

The use of rings 44 and 45 prevents leakage of air past the ends of vanes 39 and the consequent impairment of the efliciency of the separator. The air andpulverized material'carried thereby can enter the separating chamber 29 only through the inlets 39 and the vanes 38 impart to the air the required tangential angle, or whirling motion.

The centrifugal action produced by this motion causes the comparatively coarse particles of material to be moved against the wall of the outer shell or cone member 21 and then to drop into the lower end of said member. The fine particles remain in suspension in the air and are carried thereby away from the separator to discharge pipe l5.

As the collar 52 is raised, the cross sectional area of each inlet is correspondingly reduced, thereby increasing the velocity of air entering the inner or separating chamber 29 and increasing the. centrifugal action so that a finer separation of the ground material takes place.

In the modified form shown in. Figure 6, the collar 52 is adjustable by means extending downwardly and outwardly through the side wall of the outer member 26. This means consists of screw-threaded rods 59 which are secured at their upper ends to the ring or collar 52, as indicated at 50, and which rods extend downwardly and outwardly through member 26 and through bearing 6! fixed thereto. A nut 62 is revolubly arranged between abutment members 63 and 64 of each bearing BI and receives the corresponding screw 59. Thus by turning nuts 62, rods or screws 59 are raised or lowered accordingly, thereby adjusting collar 52 and regulating the size of inlets 39.

In the modified form shown in Figure 7, an adjustable collar or band 55 is shown normally To 'raise the collar 52, each rod 55 is pulled, permitting the distance of one or more apertures as the case may be, whereupon pin 58 is inserted into obtain pulverized material of a finer average particle size.

Where the ringis used in combination with the vanes, the adjustments of the latter and of the ring can be made independently of each other.

I claim:

1. In a separator of the class described, the combination of an'outer inverted cone member having its lower end forming an inlet, a top wall for closing the upper end of said cone member, an inner inverted cone-member arranged within and spaced from said outer 'member and having its lower end forming an outlet for coarse material,

an open-ended cylindrical portion arranged on the upper end of said inner member and terminating short of said top wall, a plurality of vertical, non-radial vanes arranged peripherally between the upper end of said cylindrical portion and said top wall, said vanes all forming substantially equal angles with the radii through their respective points of intersection with said cylindrical portion, said vanes being disposed within the vertical plane of said cylindrical por- ,tion and forming a plurality of inlets, a pipe extending downwardly and axially through said top wall into said inner conemember andforming an outlet for air and fine material, and a collar slidably mounted exteriorly on said cylindrical portion and movable upwardly to reduce the effective area of said inlets.

2. In a separator of the class described, the

combination of an outer inverted cone member having its lower end forming an inlet, a top wall for closing the upper end of said cone member, an inner inverted cone member arranged within and spaced from said outer member and having its lower end forming an outlet for coarse material, an open-ended cylindrical portion fixed to the upper end of said inner member and terminating short of said top wall, a plurality of vertical, non-radial vanes arranged peripherally b tween the upper end of said cylindrical portion and said top wall, said vanes all forming substantially equal angles with the radii through their respective points of intersection with said cylindrical portion, said vanes being disposed within the vertical plane of said cylindrical portion and forming a plurality of inlets, a pipe extending downwardly and axially through said top wall into said inner cone member and forming an outhaving an inlet, a top wall for closing the upper end of said cone member, an inner inverted cone member arranged within and spacedfrom said outer member and having its; lower end forming an outlet for coarse material, a cylindrical extension fixed on the upper end of said inner member and terminating short of said top wall toform an inlet opening between the upper ends of said cone member, a plurality of vertical, non-radial vanes arranged peripherally between the upper end of said cylindrical portion and said top wall, said vanes all forming substantially equal angles with the radii through their respective points of intersection with said cylindrical portion, said vanes being disposed wholly within the vertical plane of said cylindrical extension and forming a plurality of inlets, said vanes being adjustable to regulate the angle of inclination of each inlet, a pipe extending downwardly and axially through said top wall into said inner cone member and forming an outlet for air and fine material, a collar slidably and exteriorly mounted on said cylindrical extension andmovable axially thereof to reduce said inlet opening between the upper ends of said cone members and reduce accordingly the effective area of said inlets. I

4. In a separator of the class described, the

combination of an outer inverted cone member having its lower end forming an inlet, a top wall for closing the upper end of said outer cone member, an inner inverted cone member supported within said outer cone member, a cylindrical extensionflxed to the upper end of said inner cone member and terminating short of said top wall to form an inlet opening between said cones, a plurality of vertically disposed vanes arranged peripherally between the upper end of said cylindrical extension and. said top wall, each vane being of substantially greater width than the dis tance between two adjacent vanes whereby the inlet passages formed thereby are comparatively narrow and deep to insure the discharge of air and material into said inner cone member in the desired direction, said vanes being adjustable to regulate the angle of inclination of each inlet, a pipe extending downwardly. through said top wall into said inner cone memberto form an outlet therefor for air and fine material, and a collar slidably and exteriorly mounted on said cylindrical extension and adjustable axially thereof to 

